Sex Role–Dependent Behavioral and Architectural Divergence in a Jumping Spider

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  Sex Role–Dependent Behavioral and Architectural Divergence in a Jumping Spider ABSTRACT Sex differences in behavior and functional traits are often attributed to differences in mating effort intensity, but the role of sex-specific parental demands remains poorly understood. Using the jumping spider Toxeus maxillosus —where males engage in mate searching and courtship without providing parental care, while females provide extended maternal care from egg attendance to offspring maturity (around 3 months)—we conducted an exploratory investigation into whether these distinct selective pressures led to divergence in spatial behaviors and nest architecture. Results revealed that males and females showed equivalent accuracy, latency, and learning-related performance in both a route-planning test under water stress and a color-pattern associative memory task. In contrast, during nest-construction assays, females built complex, multi-entrance structures that closely matched the container'...

From sting to pacemaker: a case of complete heart block following yellow scorpion envenomation—a case report

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From sting to pacemaker: a case of complete heart block following yellow scorpion envenomation—a case report

Abstract

Background

Scorpion envenomation is a significant medical concern in tropical and subtropical regions, with cardiovascular complications being among its most severe manifestations. While scorpion venom-induced cardiac dysfunction is well-documented, complete atrioventricular (AV) block is a rare occurrence. This case highlights a unique presentation of complete heart block following a yellow scorpion sting, emphasizing the importance of early recognition and management.

Case presentation

A 56-year-old Middle Eastern (Iranian) male presented to the emergency department with dizziness, syncope, and severe bradycardia following a yellow scorpion sting. Electrocardiographic evaluation revealed a complete atrioventricular block. Laboratory findings indicated elevated cardiac biomarkers, suggesting myocardial injury. Echocardiography demonstrated left ventricular dysfunction without significant structural abnormalities. The patient required temporary transvenous pacing for hemodynamic stabilization and was managed with supportive care, including intravenous fluids, atropine, and continuous cardiac monitoring. Over the course of hospitalization, his conduction abnormality resolved by permanent pacemaker, and he was discharged in stable condition.

Conclusions

This case underscores the potential for severe cardiac complications following scorpion envenomation, particularly conduction disturbances such as complete atrioventricular block. Although rare, healthcare providers should be aware of this life-threatening consequence and initiate prompt intervention to prevent adverse outcomes. Increased awareness and timely management can significantly improve prognosis in affected patients.

Zibaeenezhad, M.J., Alizadeh, Z., Rajabi, A. et al. From sting to pacemaker: a case of complete heart block following yellow scorpion envenomation—a case report. J Med Case Reports 19, 620 (2025). https://doi.org/10.1186/s13256-025-05687-0